The Stelvio Quadrifoglio uses a Ferrari-derived V8, powering it from 0-60 mph in just 3.9 seconds with a top speed of 177mph.

Alfa Romeo

Named for a famed mountain pass, the Stelvio promises to be exciting to drive.

Alfa Romeo

Alfa Romeo has a unique interior design direction, and we like it.

Alfa Romeo

That Ferrari-based engine.

Alfa Romeo

An unlikely wedding of segments come to life in Alfa Romeo's new Stelvio, a Giulia sedan-based SUV coming to the world next year with either a mere 280hp (208kW) from the 2.0-liter Ti version, or a raucous, flame-throwing 505hp (377kW) from the Quadrifoglio top edition, shown here.

Which brings up questions. Existential questions. Comedian Stephen Wright asked years ago: "If you were in a car that could travel at the speed of light and you turned on the headlights, would they work?" Similarly, even though the world has turned to SUVs for automotive salvation, are those buyers—or even a meaningful segment of those folks—asking for thoroughbred sports car-level performance? And when is 500hp not enough? Turns out Alfa Romeo sees a niche there and has thrown a veritable kitchen sink's worth of go-fast at it, too.

Like Shakespeare, Alfa has risen in three acts from past ashes. Act 1 was the raucous, raw 4C sports car/puppy we reviewed earlier this year. Act 2 is the Giulia sedan we reported on back in March, which Alfa claims is the fastest production sedan around Germany's Nurburgring Nordschleife test track. And now, the Stelvio—named for a famous, challenging, twisty mountain pass in Northern Italy right on the Swiss border—becomes Act 3.

Generating 505hp and 443ft-lb (600Nm) of torque from a 2.9-liter twin-turbo V6 engineered with help from brother brand Ferrari, the Quadrifoglio dashes to 60mph in a claimed 3.9 seconds and a top speed of 177mph (285km/h). The turbochargers are actually part of the exhaust manifolds and operate under variable boost to improve low rpm, low exhaust velocity, and low temperature throttle response. Cylinder deactivation also allows it to momentarily be a three-cylinder engine at low loads, improving fuel efficiency, though no numbers are yet claimed.

The Alfa's Q4 AWD system can divert as much as 60 percent of the drive power to the front wheels, but it is primarily a rear-biased car. A driver-selectable drive mode system—with Dynamic, Natural, Advanced Efficiency, and Race settings—provides some flexibility and adaptability to different traction levels and road conditions. The Quad also gets a torque vectoring differential and aluminum, column-mounted paddle shifters. Alfa's upper and lower control arm front suspension is paired with a patented multi-link rear suspension.

Meanwhile, down the ladder of performance, the Stelvio and Stelvio Ti models use a 2.0-liter, direct-injection turbo four-cylinder, delivering 280hp and 306ft-lb (414Nm) of torque, figures good for 144mph (231km/h).

The Quadrifoglio really begs the question of racetrack-level performance from an SUV and who still—or ever—sought it. There's no doubt it's a small feat of engineering. Producing a near-4,000-pound SUV that can slosh five people around the Nurburgring Nordschleife faster than any other SUV and from a dead rest to 60 mph in 3.9 seconds is a real thing to Alfa. But are people clamoring for a half-soccer-practice, half-track-rat SUV? One that can keep pace with a Ferrari? We'll have to wait until the summer of 2017, when the driving curtain rises on Alfa's Act 3.